Gainotti G, Giustolisi L, Nocentini U
Institute of Neurology, Catholic University, Rome, Italy.
J Neurol Neurosurg Psychiatry. 1990 May;53(5):422-6. doi: 10.1136/jnnp.53.5.422.
To explain the prevalence of unilateral spatial neglect in patients with right brain damage, Heilman et al have suggested that the attentional neurons of the right parietal lobe might have bilateral receptive fields, whereas the homologous cells of the left hemisphere would have strictly contralateral receptive fields. One implication of this theory is that patients with right brain damage should show a prevalence of disorders of visual attention not only in the half space contralateral to the damaged hemisphere, but also in the ipsilateral one. To check this theory, 50 control subjects, 102 right and 125 left brain-damaged patients were given a drawing completion task in which patients were requested to complete the missing parts of a star, a cube and a house. Omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere were taken separately into account. Results did not confirm the hypothesis, since right brain-damaged patients failed to complete the contralateral sides of the models much more frequently than patients with left brain injury, but no difference was found between the two hemispheric groups when ipsilateral disorders of visual attention were taken into account. Furthermore, no correlation was found between omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere. This finding suggests that contralateral and ipsilateral disorders of visual attention are not due to the same mechanism in right brain-damaged patients. The alternative hypothesis viewing ipsilateral disorders as resulting from a widespread lowering of general attention (and only contralateral neglect reflecting a specific disorder of visual attention) was supported by results obtained on a verbal memory test, used to evaluate the general cognitive and attention level of the patients. Patients with clear-cut ipislateral inattention obtained very low scores on this test, whereas patients with severe contralateral neglect, but not ipislateral inattention scored within the normal range on the verbal memory test.
为了解释右脑损伤患者单侧空间忽视的患病率，海尔曼等人提出，右顶叶的注意力神经元可能具有双侧感受野，而左半球的同源细胞则具有严格的对侧感受野。该理论的一个含义是，右脑损伤患者不仅应在受损半球对侧的半空间中表现出视觉注意力障碍的患病率，而且在同侧也应如此。为了验证这一理论，对50名对照受试者、102名右脑损伤患者和125名左脑损伤患者进行了一项绘画完成任务，要求患者完成星星、立方体和房子的缺失部分。分别考虑了位于受损半球对侧和同侧的模型侧面线条的遗漏情况。结果并未证实这一假设，因为右脑损伤患者比左脑损伤患者更频繁地未能完成模型的对侧部分，但在考虑视觉注意力的同侧障碍时，两组半球之间没有发现差异。此外，在位于受损半球对侧和同侧的模型侧面线条的遗漏之间未发现相关性。这一发现表明，右脑损伤患者的对侧和同侧视觉注意力障碍并非由相同机制引起。将同侧障碍视为由一般注意力广泛降低导致（只有对侧忽视反映了视觉注意力的特定障碍）的另一种假设得到了一项言语记忆测试结果的支持，该测试用于评估患者的一般认知和注意力水平。明显存在同侧注意力不集中的患者在该测试中得分极低，而患有严重对侧忽视但无同侧注意力不集中的患者在言语记忆测试中的得分在正常范围内。
